1. Field of the Invention
The present invention generally relates to a semiconductor device and particularly relates to a manufacturing method of a semiconductor device that is packaged with a fine-structured interposer that is fabricated using a silicon substrate.
2. Description of the Related Art
In a semiconductor device of the above-described type, semiconductor chips are mounted on an interposer. Accordingly, along with recent developments in semiconductor chips having finer and thinner structures, efforts are being made to provide interposers (wiring substrates or rearranging substrates) having finer and thinner structures. Interposers are normally made by forming a stack of insulating layers and conductive layers that serve as interconnections.
Recently, it has been proposed to fabricate interposers using a fine-machining technique such as a photolithography technique used in a semiconductor chip manufacturing device. Generally, in such an interposer manufacturing process using a photolithography technique, interconnection patterns and insulating layers are stacked on one side of a silicon substrate and lands of external connection mounting terminals are formed on the other side of the silicon substrate. The lands and the interconnection patterns which are on opposite sides of the silicon substrate are electrically connected by vias formed through the silicon substrate.
By using a silicon substrate, wiring patterns and insulating layers of an interposer can be formed in a manner similar to a process of manufacturing a semiconductor chip. Therefore, there is an advantage that a fine- and multilayer-structured interposer can be formed.
According to the above-mentioned interposer manufacturing method using a silicon wafer, it is necessary to perform the steps of forming through-holes in the silicon substrate for providing vias connecting front and sides the interposer, give an insulation treatment in which SiO2 layers are formed on inner surfaces of the through-holes and filling the through-holes with plating layers. The silicon substrate has a certain thickness for sustaining sufficient strength during the interposer manufacturing process. Therefore, in order to form through-holes through such a silicon substrate and to give insulation and plating treatments on the inner surfaces of the through-holes, expensive devices are used with increased machining time. This results in an increase of manufacturing cost for interposers.
The silicon substrate itself is provided for sustaining the strength and is not necessary for the function of the interposer. However, since the thickness of the silicon substrate itself is greater than the thicknesses of the wiring patterns and the insulation layers, an overall thickness of the interposer becomes comparatively great due to the thickness of the silicon substrate.
Further, in a process step of filling the plating layers in the through-holes, it is technically difficult to prevent voids in the plating layer that may lead to lower conductivity and reduced reliability.
Further, since the silicon substrate is very thin, it is difficult to handle the interposer as a single body during a manufacturing process.
Also, there is a problem with the semiconductor device in which the silicon substrate is provided with an interposer attached on one side and an insulating layer attached on the other side in that the interposer itself might warp. In such a case, it is difficult to mount LSI chips having fine-pitched electrodes onto the interposer.
Accordingly, it is a general object of the present invention to provide a method of manufacturing semiconductor devices that can obviate the problems described above.
It is another and more specific object of the present invention to provide a method of manufacturing a semiconductor device with an interposer wherefrom a silicon substrate for sustaining the strength during manufacture is removed.
In order to achieve the above objects, the present invention provides a method of manufacturing a semiconductor device using a wiring substrate, which includes the steps of:
a) forming a peelable resin layer on a silicon substrate, the peelable resin layer having a lower adhesiveness to the silicon substrate and being easily peelable from the silicon substrate;
b) forming the wiring substrate on the peelable resin layer;
c) mounting a plurality of semiconductor chips on the wiring substrate;
d) forming semiconductor devices by sealing the plurality of semiconductor chips by a sealing resin;
e) individualizing the semiconductor devices by dicing the semiconductor devices from the sealing resin side but leaving the silicon substrate;
f) peeling each of the individualized semiconductor devices from the silicon substrate such that the silicon substrate and the peelable resin layer are separated; and
g) exposing terminals provided on the wiring substrate by forming openings through the peelable resin layer or by removing the peelable resin layer.
According to the invention described above, the silicon substrate can be easily peeled off from the semiconductor devices by providing the peeling resin layer. Therefore, it is no longer necessary to perform a step of exposing terminals of the wiring board by processing the silicon wafer. Also, the thickness of the semiconductor device can be reduced by a thickness of the silicon substrate to be removed.
The present invention further provides a method of manufacturing the semiconductor device using a wiring substrate, which includes the steps of:
a) forming a peelable resin layer on a silicon substrate, the peelable resin layer having a lower adhesiveness to a wiring substrate and being easily peelable from a wiring substrate;
b) forming the wiring substrate on the peelable resin layer;
c) mounting a plurality of semiconductor chips on the wiring substrate;
d) forming semiconductor devices by sealing the plurality of semiconductor chips by a sealing resin;
e) individualizing the semiconductor devices by dicing the semiconductor devices from the sealing resin side but leaving the silicon substrate; and
f) peeling each of the individualized semiconductor devices from the silicon substrate such that the silicon substrate and the peelable resin layer are separated.
According to the invention described above, the silicon substrate and the peelable resin can be easily peeled off from the semiconductor devices by providing the peeling resin layer. Therefore, it is no longer necessary to perform a step of exposing terminals of the wiring board by processing the silicon wafer. Also, the thickness of the semiconductor device can be reduced by a thickness of the silicon substrate to be removed. Also, the peelable resin layer may be removed.
The present invention further provides a method of manufacturing the semiconductor device using a wiring substrate, including the steps of:
a) forming a peelable resin layer on a silicon substrate, the peelable resin layer having a lower adhesiveness to the silicon substrate and being easily peelable from the silicon substrate;
b) forming the wiring substrate on the peelable resin layer;
c) mounting a plurality of semiconductor chips on the wiring substrate;
d) forming semiconductor devices by sealing the plurality of semiconductor chips by a sealing resin;
e) thinning the silicon substrate by a grinding process;
f) peeling the semiconductor devices from the silicon substrate with the peelable resin layer being attached to the thinned silicon substrate such that the silicon substrate and the peelable resin layer are separated;
g) individualizing the semiconductor devices by dicing the semiconductor devices; and
h) exposing terminals provided on the wiring substrate by forming openings through the peelable resin layer or by removing the peelable resin layer.
According to the invention described above, the silicon substrate becomes flexible by thinning the silicon substrate, and as a result of a synergy effect with the low-adhesiveness of the peelable resin layer, the silicon substrate can be easily peeled off from the semiconductor device. Therefore, it is no longer necessary to perform a step of exposing terminals of the wiring board by processing the silicon wafer. Also, the thickness of the semiconductor device can be reduced by a thickness of the silicon substrate to be removed.
The present invention further provides a method of manufacturing the semiconductor device using a wiring substrate, including the steps of:
a) forming a peelable resin layer on a silicon substrate, the peelable resin layer having a lower adhesiveness to a wiring substrate and being easily peelable from a wiring substrate;
b) forming the wiring substrate on the peelable resin layer;
c) mounting a plurality of semiconductor chips on the wiring substrate;
d) forming semiconductor devices by sealing the plurality of semiconductor chips by a sealing resin;
e) thinning the silicon substrate by a grinding process;
f) peeling the semiconductor devices from the silicon substrate with the peelable resin layer being attached to the thinned silicon substrate such that the silicon substrate and the peelable resin layer are separated; and
g) individualizing the semiconductor devices by dicing the semiconductor devices.
According to the invention described above, the silicon substrate becomes flexible by thinning the silicon substrate, and as a result of a synergy effect with the low-adhesiveness of the peelable resin layer, the silicon substrate can be easily peeled off from the semiconductor device. Therefore, it is no longer necessary to perform a step of exposing terminals of the wiring board by processing the silicon wafer. Also, the thickness of the semiconductor device can be reduced by a thickness of the silicon substrate to be removed.
The present invention further provides a method of manufacturing the semiconductor device using a wiring substrate, including the steps of:
a) forming a peelable resin layer on a silicon substrate, the peelable resin layer having a lower adhesiveness to the silicon substrate and being easily peelable from the silicon substrate;
b) forming the wiring substrate on the peelable resin layer;
c) mounting a plurality of semiconductor chips on the wiring substrate;
d) forming semiconductor devices by filling insulating resin between the plurality of semiconductor chips and the wiring substrate;
e) adhering a frame-like member on the silicon substrate such that the frame-like member surrounds each of the plurality of semiconductor chips, the frame-like member being made of a material having a higher rigidity than that of the wiring substrate;
f) individualizing the semiconductor devices by dicing the semiconductor devices from the frame-like member side but leaving the silicon substrate;
g) peeling each of the individualized semiconductor devices from the silicon substrate such that the silicon substrate and the peelable resin layer are separated; and
h) exposing terminals provided on the wiring substrate by forming openings through the peelable resin layer or by removing the peelable resin layer.
According to the invention described above, the semiconductor device can be maintained substantially flat by the rigidity of the frame-like member and therefore deformation of the semiconductor chip can be prevented.
The present invention further provides a method of manufacturing the semiconductor device using a wiring substrate, including the steps of:
a) forming a peelable resin layer on a silicon substrate, the peelable resin layer having a lower adhesiveness to a wiring substrate and being easily peelable from a wiring substrate;
b) forming the wiring substrate on the peelable resin layer;
c) mounting a plurality of semiconductor chips on the wiring substrate;
d) forming semiconductor devices by filling insulating resin between the plurality of semiconductor chips and the wiring substrate;
e) adhering a frame-like member on the silicon substrate such that the frame-like member surrounds each of the plurality of semiconductor chips, the frame-like member being made of a material having a higher rigidity than that of the wiring substrate;
f) thinning the silicon substrate by a grinding process;
g) peeling the semiconductor devices with the peelable resin layer being attached to the thinned silicon substrate such that the wiring substrate and the peelable resin layer are separated; and
g) individualizing the semiconductor devices by dicing the semiconductor devices.
According to the invention described above, the semiconductor device can be maintained substantially flat by the rigidity of the frame-like member and therefore deformation of the semiconductor chip can be prevented.
The present invention further provides a semiconductor device including:
a thin-film multilayer substrate;
at least one semiconductor chip mounted on the thin-film multilayer substrate;
a package substrate whereto the thin-film multilayer substrate is connected; and
external connection terminals provided on the package substrate,
wherein the thin-film multilayer substrate is fixed to the package substrate.
According to the invention described above, the thin-film multilayer substrate itself is fixed on the package substrate by material such as solder, and therefore, a silicon substrate for sustaining the strength of the thin-film multilayer substrate can be dispensed with. Accordingly, the height (thickness) of the semiconductor device can be reduced. Also, there is no need to provide conductive parts that penetrate through the silicon substrate and therefore any defect originating from the conductive parts can be prevented and the manufacturing cost can be reduced.
The present invention further provides a method of manufacturing the semiconductor device, including the steps of:
a) forming a metal thin-film layer on a silicon substrate;
b) forming a thin-film multilayer substrate by forming conductive layers and insulating layers in multiple levels on the metal thin-film layer;
c) attaching a supporting member on the thin-film multilayer substrate by means of an adhesive member;
d) removing the silicon substrate and the metal thin-film layer;
e) individualizing the thin-film multilayer substrate together with the supporting member;
f) mounting the thin-film multilayer substrate on a package substrate and fixing the thin-film multilayer substrate on the package substrate;
g) reducing adhesiveness of the adhesive member and peeling the supporting member and the adhesive member from the thin-film multilayer substrate; and
h) mounting semiconductor chips on the thin-film multilayer substrate.
According to the invention described above, even if the silicon substrate is removed, the thin-film multilayer substrate is held in a flat state and therefore easy handling can be achieved without deforming the thin-film multilayer substrate.
The present invention further provides a semiconductor device including:
a thin-film multilayer substrate;
at least one semiconductor chip mounted on the thin-film multilayer substrate;
a package substrate whereto the thin-film multilayer substrate is connected; and
external connection terminal provided on the package substrate,
wherein the semiconductor chip is sealed on the thin-film multilayer substrate by means of a sealing resin such that the back surface of the semiconductor chip is exposed from the sealing resin, and
the thin-film multilayer substrate is fixed to the package substrate.
According to the invention described above, since the thin-film multilayer substrate is held in a flat state with the semiconductor chips mounted thereon and by the sealing resin, the silicon substrate that is provided for sustaining rigidity during the manufacturing process can be dispensed with. Thus, the height (thickness) of the semiconductor device can be reduced. Also, there is no need to provide conductive parts that penetrate through the silicon substrate. Therefore, defects related to the conductive parts can be prevented and thus the manufacturing cost can be reduced.
The present invention further provides a method of manufacturing the semiconductor device, including the steps of:
a) forming a metal thin-film layer on a silicon substrate;
b) forming a thin-film multilayer substrate by forming conductive layers and insulating layers in multiple levels on the metal thin-film layer;
c) mounting at least one semiconductor chip on the thin-film multilayer substrate;
d) resin sealing the semiconductor chip on the thin-film multilayer substrate;
e) removing the silicon substrate and the metal thin-film layer;
f) individualizing the thin-film multilayer substrate; and
g) mounting the individualized thin-film multilayer substrate on a package substrate and fixing the thin-film multilayer substrate on the package substrate.
According to the invention described above, even if the silicon substrate is removed in the manufacturing process, the thin-film multilayer substrate can be held in a flat state by the semiconductor chips and the sealing resin. Thus, easy handling of the thin-film multilayer substrate can be acheived.